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Monochrome TTL monitor (MDA / Hercules) with amber phosphor

PostPosted: Tue Oct 04, 2016 10:22 am
by AlexC
I'm looking for a 9-pin TTL monitor for use with an MDA and Hercules graphics adapter in an 8088 PC. Must be amber phosphor, very little or no burn-in, good working condition. Must be 220-240V for New Zealand mains power.

Happy to pay a reasonable price plus postage and packing - must be very carefully packaged, obviously.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 04, 2016 10:41 am
by LS120
will look but think i may only have a mono vga (b&w) left...

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 04, 2016 3:40 pm
by AlexC
Thanks. I like those too, but I already have enough of them.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 04, 2016 3:56 pm
by LS120

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 04, 2016 4:49 pm
by mons2b
I was going to suggest the same thing. I dont know if Paperwhite is amber or not.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 04, 2016 7:12 pm
by AlexC
No, that's white phosphor. I did actually buy one of those but they will only work with the Amstrad PC1640 because they require a power draw on the supply line before they'll switch on. The seller sent me a schematic to trick the monitor into thinking it has a load using resistors, but the resistor values are only guesses and so far I've had no luck.

But it's amber that I'm after. I like the orange glow.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Thu Oct 13, 2016 11:52 am
by SpidersWeb
I bought one of those too. I did get mine started after presenting an artificial load, but had sync problems, probably needs new electrolytic caps.

MDA is hard to find here, I do have one Amber unit but unfortunately it's my test monitor and I don't want to part with it, but it's in poor condition with bad screen burn anyway.
Good luck with the search!

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Thu Oct 13, 2016 2:03 pm
by AlexC
Don't suppose you have a schematic for the artificial load, do you? The seller sent me one schematic that didn't work, then a replacement that also didn't work... though it's possible that the first one damaged something in the monitor.

He was good about it and made amends, but it would be nice to try to get that monitor working with a known-good load circuit.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Fri Oct 14, 2016 11:57 am
by SpidersWeb
I took it apart and loaded down the +5 and +12 with a random hard drive I had laying about.

No schematic for a load, but it's pretty easy to work out. Some quick math I did in notepad:

2 or 5W 120 ohm resistor across +12 and GND would sink 100mA (1.2 watts dissipated)
1 or 2W 50 ohm resistor across +5 and GND would sink 100mA (0.5 watts dissipated)

I'd hope (but can't confirm) that would be enough of a load without causing excessive heat, nor needing to be removed if it was used to power an Amstrad PC later on.

Monitor schematics are in with the Amstrad PC manual, http://www.retroisle.com/amstrad/pcs/Or ... ereado.pdf

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 18, 2016 6:59 am
by SpidersWeb
Noticed this listing when I got up this morning

http://www.trademe.co.nz/computers/vint ... 188410.htm

Amber MDA with a Commodore PC10 hanging off it.

Re: Monochrome TTL monitor (MDA / Hercules) with amber phosp

PostPosted: Tue Oct 18, 2016 8:13 pm
by AlexC
Thanks for the notes on the Amstrad. I'll give that a try when I have some spare time. I didn't have the monitor schematic before - that'll help.

And thanks for the heads-up on the auction.